A good example is tonight's game between second-ranked Ohio State and lowly IUPUI. The Jaguars lost to the Buckeyes by 11, so just seeing the final score scroll across the bottom of your TV — 75-64 — you might not give the game a second thought. But average margin reveals a surprisingly tight contest. Here's the tweet for that game:
*ohio state 75* iupui 64 | avg margin: ohio state +0.8 #closerthanthat http://goo.gl/LIzV4
Ohio State in fact only took control late and so won average margin by less than 1 point.
That tweet also includes a tag "#closerthanthat" which is applied to games in which average margin reveals a much closer game than the final score would indicate. The reverse case, in which a close final score fails to reflect a game that one team actually had control of, I tag with "#notthatclose". Here's an example:
*unlv 75* boise state 72 | avg margin: unlv +12.5 #notthatclose http://goo.gl/wIB8L
UNLV was in control of this game most of the way — Boise State only made a push late to close the gap.
Finally, tweets can include another tag, "#veryclose", that indicates that a game's final score was close *and* the average margin was close, which probably means a great game to watch. Another example:
*missouri 85* vanderbilt 82 | avg margin: missouri +0.6 #veryclose http://goo.gl/zwLge
As you can see from following the link, the game was within a bucket or two almost the entire way.
There are a few other things I might add at some point, including the difference between the average margin and the spread, but this is a start.
PS To calculate average margin I use game flow data from StatSheet.
